1. Field of the Invention
The present invention relates to a feature information collecting device and a feature information collecting program that recognizes the image of a feature included in image information obtained from an imaging device or the like mounted in a vehicle and collects information of the feature, as well as a vehicle position recognizing device and a navigation device using them.
2. Description of the Related Art
Accompanying improvement in imaging devices and image recognition technologies in recent years, it has become more common to develop a technology for performing image recognition processing of image information obtained by imaging the surrounding area of a vehicle by an on-vehicle camera, and correcting vehicle position information representing the current positing of the vehicle based on surrounding conditions of the vehicle indicated in the image recognition result. For example, the vehicle position recognizing device described in Japanese Patent Application Publication No. JP-A-2007-271568 is structured to perform image recognition processing of a target feature included in image information obtained by an imaging device mounted in a vehicle, and check the image recognition result with feature information of this target feature stored in advance in a database to thereby correct the vehicle position information obtained by a GPS signal or autonomous navigation. Thus, highly precise vehicle position information can be obtained.
Incidentally, for correcting vehicle position information by such a vehicle position recognizing device, it is necessary to prepare a highly accurate database of feature information. To collect such feature information, there is a known device which collects feature information based on an image recognition result of a feature included in image information of the surrounding area of a vehicle obtained from an imaging device or the like mounted in the vehicle (for example, refer to Japanese Patent Application Publication No. JP-A-2006-038558 and Japanese Patent Application Publication No. JP-A-2006-275690). Incidentally, all of the devices described in Japanese Patent Application Publication No. JP-A-2007-271568, Japanese Patent Application Publication No. JP-A-2006-038558 and Japanese Patent Application Publication No. JP-A-2006-275690 take a traffic sign or a road traffic information display board provided on a road as a target feature. Then, these devices perform image recognition of a target feature included in image information obtained by an imaging device mounted in the vehicle, and associate feature information such as sign information extracted from the recognition result thereof with position information and/or section information and store them in a map database. At this time, the position information and/or section information associated with the feature information is determined based on information from a GPS receiver, a gyro, a vehicle speed sensor and the like used generally in navigation devices. Thus, a database of feature information is created in these devices, and a route search, driving support, and the like based on the database is possible.